Peel the asparagus and cut off the dry ends. Cook in
salted water until al dente, strain, rinse and drain well.
For the sauce, drain the tuna well in a sieve. Finely purée the tuna,
cream, yoghurt and oil with a hand blender. Season with salt and lemon
For the garnish, drain the capers well and wash the rocket. Arrange the
sauce on plates. Halve the thick asparagus, arrange on the sauce and
garnish with capers and rocket.